Briefcase



FIG. 1 is a top left side perspective view;

FIG. 2 is a front elevational view;

FIG. 3 is a top plan view;

FIG. 4 is a left side view;

FIG. 5 is a bottom plan view; and,

FIG. 6 is a rear elevational view. 

The ornamental design for a briefcase, as shown. 